The Cambrian Railways grew from a small line connecting Newtown and Llanidloes which opened in 1864, and in its peak stretched from Oswestry to Pwllheli and Aberystwyth and down to Tal y Llyn Junction in the South. Although the line was built as a common carrier, many slates were carried from the Blaenau, Corris, Tanat Valley and Merioneth slate mining districts.